Achilles de khotinsky



A. DE KHOTINSKY.

(No Model.)

LIGHTNING ARRESTER.

No. 571,669. Patented Nov. 17, 1896.

Izzramfior.

V UNITED STATES PATENT OFFICE.

AOIIILLES DE KIIOTINSKY, OF BOS ON, MASSAUIIUSE'I S, ASSIGNOR "O Tl IEAMERICAN BELL TELEPHONE COMPANY, OF SAME PLACE.

LlGHTNlNG-ARRESTER.

SPECIFICATION forming part of Letters Patent No. 571,669, dated November17, 1896.

Application filed September 24, 1896. Serial No. 606,877. (No model.)

T0 on whom it may concern:

Be it known that I, AOHILLES DE Kno'rm- SKY, residing at Boston, in thecounty of Suffolk and State of Massachusetts, have invented certainImprovements in Protective Appliances for Electrical Circuits, of whichthe following is a specification.

The present invention relates to an improved form of carbon-plateprotective appliances for electrical circuits.

The ordinary form of instrument-protector, consisting of two carbonplates separated by an air or spark gap, is not entirely satisfactory byreason of the occasional short-circuiting of the plates, which seems tobe chiefly if not wholly caused by slight discharges through theair-gap, resulting from static charges on the line, or secondarylightning discharges. These discharges apparently disengage smallparticles of the carbon surface, which are blown against and becomeattached to the surface of the interposed mica septum, formingconducting bridges between the plates along the inner edges of theseptum. Such eonducting-bridges, in addition to their ill eifects ingrounding and short-cireuiting the line, are disadvantageous becausethey favor discharges along the edges of the mica septum, which in timebecomes perforated and disintegrated.

The invention aims to avoid the formation of conducting orshorteircuiting bridges be tween the separated carbon plates, and thisis etfectuated by the formation of comparatively deep grooves in theopposing or proximate surfaces of the plates, extendinglongitudinallyand transversely thereof along and within their edges, and in formingthe size of the central opening in the mica-separator so that its edgeswill be in the central or axial line of the intersecting grooves. Bythis arrangement the inner edges of the mica-sop arator do not come incontact with the surfaces of the plates, and when a discharge takesplace the momentary expansion of the air within the grooves, due to theheat occasioned by the discharge, causes a rush of air, and anydisintegrated carbon particles are carried outward through the grooves.The septum is made of the same length and breadth as the carbon plates,and when it is placed between them and pressed by the fingers on allsides it assume the proper adjustment without f urther attention beingnecessary. The edges of the grooves and external edges of the plates arepreferably rounded, so that the edges of the mica-separator will be atsuch a distance therefrom that sparks will not readily pass around theseparator.

Referring to the drawings, Figure l represents in perspective theinvention showing the carbon plates and mica septum separated from eachother to show their relation to one another. Fig. 2 is a top view of themica septum with a carbon plate underneath. Fig. 3 is a section on line.r so of Fig. 2. Fig. 3 is an enlarged sectional view of two carbonplates and mica septum slightly separated from each other, and Fig. Iillustrates the utilization of the protective appliances with anelectric circuit.

a and a? are two carbon plates made precisely alike, and 7/ is the micaseptum placed between them. In practice these plates are held in asuitable support and may be con-r nected to the circnit-conduetors, asshown in Fig. 4', which represents two protector devices A A in acommonsupport connected by branches to each conductor m of the circuit L andwith a common connection to ground G, M representing the apparatus to beprotected.

In the protection of a grounded circuitit is obvious that one protectoronly would be required under conditions otherwise identical.Comparatively deep intersecting grooves 1 1 and 2 2 are formed in onesurface of the carbon plates a a near to its edges. These may be of anydesired cross-section, the rectangular section shown in the drawingsbeing preferable, and the edges 72 of the grooves and the external edges1' of the plates are cha-mfered or rounded, as shown.

The opening in the mica septum or separator is so proportioned that whenthe said separator is placed between the carbon plates the edges thereofwill coincide with or be directly over the central or axial line of theintersecting grooves in the plates.

I propose to employ a drop of easily-fusible metal with one or both ofthe carbon plates, as shown in the Patent No. 438,788, granted to A. C.\Vhite, secured, however, to the said plates in a novel manner.

I form in each plate a funnel-shaped orifice f, as shown in plate a ofFig. 3, with a small passage 6 from the bottom thereof to the oppositeside. hen the fusible drop g is run in, it fills the orifice andpassage, and a knob of the metal is formed at the end of the passage.Instead of the passage 6 extending to the opposite side of the plate itmay end in an enlargement p in the central part thereof, as shown inplate a and when the metal is run in it fills the space 1) and serves tolock the metal into the plate. By this construction the fusible drop isheld in place so that it cannot fall out, and when fused, owing to theangular sides of the oriflee, the melted metal flows quickly to thesurface of the opposite carbon and cools,

forming a bridge for the current from plate to plate.

Having now fully described the invention, I claim 1. A spark or air gapprotective appliance, consisting of two carbon plates having theirproximate surfaces grooved or channeled; and a centrally-slottednon-conducting septum between them, the edges of the slot coincidingwith the axial or central lines of the said channels.

2. In a spark or gap protective appliance, the combination of carbonline and earth plates in close proximity to each other, and

provided with longitudinal and transverse grooves or channels in theirproximate surfaces, with an interposed septum of mica or likenon-conductor having a slot in its central part whose edges coincidewith the axial. lines of the channels in the said plates, as set forth.

3. A spark or air gap protective appliance consisting of two carbonplates having their proximate surfaces grooved or channeled andv theiredges chamfered or rounded; and a centrally-slotted non-conductingseptum between the said surfaces of the same size thereof, the edges ofthe slot coinciding with the axial lines of the said channels,substantially as described.

4:. A spark or air gap protective appliance consisting of two carbonplates one of which has an angular-shaped mass of easily-fusibleconducting material embedded in its approxi- I mate surface having ahooking or locking extension; and a centrally-slotted non-conductingseptum between the said plates, the edges of the slot coinciding withthe axial lines of the said channels, as set forth.

In testimony whereof I have signed my name to this specification, in thepresence of two subscribing witnesses, this 21st day of September, 1896.

ACHILLES DE KIIO'FINSK'Y. lVitnesses:

GEO. WILLIs PIERCE, J osEPH A. GATELY.

